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K4 - Power Curves

We have tried to represent the suggested cut off between the installation of the the KFP - K3 and the KFP - K4. Installations below the middle purple line we would recommend the K3 - above the line K4.

There is obviously an area of overlap. Larger heavier displacement vessels are always better matched to a propeller with increased blade area. K4 units have roughly 33% more blade area for a given diameter.

We suggest you contact us to discuss what is appropriate for your yacht   ....

Power on Y-axis is Horse Power - Multiply by 0.75 to convert to kW:


Below is a graph updated with current information as at September 2019 of actual K4 installations. 

You can extrapolate reasonably accurate power curves where different pitchº settings are required. In some situations such as a 62 hp engine with 1400 shaft rpm which sits midway between an 18.00" and 19.50" unit - choices can be made with appropriate pitch adjustments and trade-offs between achieving max rated engine rpm and improved cruise speeeds at cruise rpm.

On the Y or vertical axis is Hp @ max rpm - the X or horizontal axis the shaft rpm @ max